Post alignment

Hello,

i’m running croatia’s nightlife site. The problem is with alignment of posts. You can see example here: http://croatiaclubbing.com/rijeka/
Everything is great aligned till 5th row. There is just one post and should be 4. Problem repeats all over the site, everything is good but now and then “anomaly” like this appears.
I tried playing with widths but nothing seems to solve it.

Anybody got some clue?

Thanks,
Luka